Automated data storage libraries provide a means for storing large quantities of data in removable data storage media, such as magnetic tape data storage cartridges, that are not permanently mounted on data storage drives, and that are stored in a readily available manner on storage shelves.
Data is written to a magnetic tape data storage cartridge by a magnetic tape data storage drive, and the cartridge is typically removed from the drive and stored in a storage shelf of the automated data storage library and at some subsequent time is accessed from the storage shelf to be read by the same or another magnetic tape data storage drive of the library. Should an application or applications not cycle through multiple drives, for example, all jobs start on the same drive, and if that drive is busy try the next, errors in the data transfer process, for example, from defective cartridges, will be concentrated in the first drive. Thus, the assumption may be made that the problem lies with the magnetic tape data storage drive, resulting in the replacement of the drive, with accompanying warranty expense by the drive supplier, and may result in replaced and returned drives having “no defect found”. One approach is to interrupt the application experiencing data errors, to move cartridges that have evidenced errors from drive to drive, and test the cartridges in another drive. This approach is not necessarily appreciated by the user of the library and cartridges.